It seems a lot of people still want to login to there asterisk boxes as root. And for the most part no one seems to (or i have not seen) be will to explain the reason this is NOT a good ideal. I will save the preaching for those more qualified then my self. However using the SUDO command is a lot safer. It allows you to review what commands have been issued. control what commands can be issued and generally give a user access to a subset of features that are only needed for there use. (i.e not allowing a user to use ifconfig) It is a safety net. And a very good start. However the simple rule of SUDO is, this. any command you would normally need root for you simply type sudo first. That being said, if you do not know the root password simply issue :

sudo passwd root
and you will be prompted for a new password for the root user.

sudo su -
will dump you in to a root shell with roots configs loaded (after you provide a password of course)

so ssh in to your boxes as admin people and then use the sudo command to carry out your commands. IF you MUST use root the two line above will work of you, with out having to do anything crazy like booting to a single user mode. or the bang ! at the CLI prompt (which makes me nervous personally)